Conventionally, metal spikes of a needle-like shape are widely used as spikes for golf shoes. Owing to the metal spike, for example, even on a wet green slope, a strong gripping force is obtained.
However, since such metal spike ensures the gripping force by sticking into the green up to the soil layer thereof, the green surface after a wearer of the metal spike has walked thereon gets into a state where the green is slightly dug up. Particularly, on a putting green, this may cause some problems for the next play. Also, when a wearer of the conventional metal spike walks on a carpet in a clubhouse, it may cause damage to the carpet resulting in a problem.
Further, when a wearer of the metal spike walks on a hard ground such as a pavement, the wearer feels a stick-up feeling at the area of the spike. The wearer may also feel some instability while walking due to the small number of points supporting his/her weight. Thus, golf shoes equipped with the above-described metal spikes are also uncomfortable for the wearer. Still further, because the impact from the ground is transferred directly to the human body, there arises such problem that fatigue is accumulated on the feet, knees and waist bearing the impact.
In order to solve the above problems, spikes for golf shoes called “non-metal spikes” made from synthetic resin are now used. Owing to the resin spike, the wearer is free from stick-up feeling even on a hard road surface. Since there are many points that support the weight, stability is also obtained while walking.
As a resin spike as described above, there has been proposed a spike made from synthetic resin, which is disclosed in Japanese Unexamined Patent Application Publication No. H11-262401 corresponding to U.S. Patent Application No. 60/070735; and a spike made from synthetic resin disclosed in Japanese Patent Application No. 2000-14944 applied by the applicant of the present invention.